Various photosensitive polyacetylenic compounds their dispersions in binder and methods of exposure have been disclosed in several patents including U.S. Pat. Nos. 4,066,676; 4,581,315; 3,501,302; 3,772,027 and 3,954,816. All of these imaging systems require the use of radiation sensitive polyacetylenic crystals uniformly and fixedly dispersed in an aqueous binder which forms a layer on a film substrate. The recording of image information on many polyacetylenic films has presented several problems and shortcomings, such as an inadequate degree of resolution, limitations related to certain sources of radiation for adequate exposure, inferior image color density and color instability. Other deficiencies include a relatively slow development of the image and, in certain cases, the need for imaging at extremely low temperatures in order to maintain receptivity of the polyacetylenic compound. Among the more sensitive polyacetylenic compounds which respond to development on exposure to radiation from many sources are the conjugated diacetylenes containing a hydrophilic group which promotes hydrogen bonding so that polyacetylene in adjacent molecules can be properly aligned for polymeriation.
It has been found however that, even among these species, the degree of sensitivity varies widely so that some have a relatively low radiation sensitivity which is best imaged in the short wavelength portion of the spectrum. Others exhibit a higher sensitivity toward the desired longer wavelength portions. Regardless of the species selected for imaging, it is always desirable to maximize sensitivity so as to achieve one or more benefits which include increasing the speed of response to exposure, the ability to employ lower dosages and expanding the wavelength sensitivity of polyacetylenic films.
Accordingly, it is an object of this invention to achieve the above benefits by an economical and commercially feasible process.
Another object is to provide a product which has markedly improved image receptivity.
Still another object is to provide a new and unique polyacetylenic crystalline composition disposed in a suitable binder.
These and other objects of the invention will become apparent from the following description and disclosure.